> ... part of the reasons that Trump wants Greenland is to site ICBM detection and interceptor systems.

Nothing is stopping the US from deploying those in Greenland right now.

The only reason Trump wants Greenland is he's not all there -- Greenland looks big on the map so he's fixated on it.

> Nothing is stopping the US from deploying those in Greenland

That would require the (politically unlikely) agreement of the Danish government. See article 2 of the relevant treaty [1]:

"...establishing and/or operating such defense areas as the two Governments, on the basis of NATO defense plans, may from time to time agree to be necessary..."

> The only reason Trump wants Greenland is he's not all there -- Greenland looks big on the map so he's fixated on it.

I agree that that is part of it, but there is more to it than that.

[1] https://avalon.law.yale.edu/20th_century/den001.asp

Why wouldn't Denmark agree? Danish and Greenlandic politicians have reminded the US several times that more bases can be established under the terms of this treaty.

E.g. https://www.bbc.com/news/articles/cx21669452lo

So, you're saying the US (300+ mln, #1 military) never actually requested to deploy them and Denmark (5 mln) never actually refused. But because you think an agreement is unlikely, it's straight to annexation by force. Do I have that right?

No, I'm saying that new military installations would be unlikely to be agreed due to domestic political sentiment. Pituffik was certainly agreed by both sides, but that was a long time ago.

(I'm not Danish or Greenlandic, so this is just my reading of the situation.)

You are reading wrong, and should maybe stop chiming in on stuff you have no idea about. An active agreement about US basing on Greenland exist, and has existed for a long time.